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Categories: Paleontology: Climate
Published Deciphering the intensity of past ocean currents
(via sciencedaily.com) Original source Ocean currents determine the structure of the deep-sea ocean floor and the transport of sediments, organic carbon, nutrients and pollutants. In flume-tank experiments, researchers have simulated how currents shape the seafloor and control sediment deposition. This will help in reconstructions of past marine conditions.
Published Scientists investigate Grand Canyon's ancient past to predict future climate impacts
(via sciencedaily.com) Original source A team explores relationship between warming post-Ice Age temperatures and intensifying summer monsoon rains on groundwater reserves.
Published Climate and human land use both play roles in Pacific island wildfires past and present
(via sciencedaily.com) Original source It’s long been understood that human settlement contributes to conditions that make Pacific Islands more susceptible to wildfires, such as the devastating Aug. 8 event that destroyed the Maui community of Lahaina. But a new study from fire scientist shows that climate is an undervalued part of the equation.
Published Ancient plant wax reveals how global warming affects methane in Arctic lakes
(via sciencedaily.com) Original source In a new study, researchers examined the waxy coatings of leaves preserved as organic molecules within sediment from the early-to-middle Holocene, a period of intense warming that occurred due to slow changes in Earth's orbit 11,700 to 4,200 years ago. They found that warming potentially could lead to a previously under-appreciated flux in methane emissions from lakes.
Published New study removes human bias from debate over dinosaurs' demise
(via sciencedaily.com) Original source Researchers tried a new approach to resolve the scientific debate over whether it was a giant asteroid or volcanoes that wiped out the dinosaurs -- they removed scientists from the debate and let the computers decide. The researchers created a model powered by 130 interconnected processors that, without human input, reverse-engineered the Cretaceous-Paleogene mass extinction until they reached a scenario that matched the fossil record. The model determined that while a meteorite contributed to the cataclysm, the outpouring of climate-altering gases from the nearly 1-million-year eruptions of volcanoes in western India's Deccan Traps would have been sufficient to trigger the extinction and clear the way for the ascendance of mammals.
Published Antarctica's glacial border migrates for miles with the tide
(via sciencedaily.com) Original source New measurements of how boundary between onshore glacier and floating ice shelf glides back-and- forth could help predict melting.
Published New research reveals extreme heat likely to wipe out humans and mammals in the distant future
(via sciencedaily.com) Original source A new study shows unprecedented heat is likely to lead to the next mass extinction, akin to when the dinosaurs died out, eliminating nearly all mammals in some 250 million years time.
Published New research reveals why and when the Sahara Desert was green
(via sciencedaily.com) Original source A pioneering study has shed new light on North African humid periods that have occurred over the past 800,000 years and explains why the Sahara Desert was periodically green.
Published Bursting air bubbles may play a key role in how glacier ice melts
(via sciencedaily.com) Original source New research has uncovered a possible clue as to why glaciers that terminate at the sea are retreating at unprecedented rates: the bursting of tiny, pressurized bubbles in underwater ice.
Published Stability inspection for West Antarctica shows: marine ice sheet is not destabilized yet, but possibly on a path to tipping
(via sciencedaily.com) Original source Antarctica's vast ice masses seem far away, yet they store enough water to raise global sea levels by several meters. A team of experts has now provided the first systematic stability inspection of the ice sheet's current state. Their diagnosis: While they found no indication of irreversible, self-reinforcing retreat of the ice sheet in West Antarctica yet, global warming to date could already be enough to trigger the slow but certain loss of ice over the next hundreds to thousands of years.
Published Scientists zero in on timing, causes of ice age mammal extinctions in southern California
(via sciencedaily.com) Original source Radiocarbon dating on bones in the La Brea Tar Pits lead archaeologists to warn that history may be repeating itself.
Published Key role of ice age cycles in early human interbreeding
(via sciencedaily.com) Original source Recent paleogenomic research revealed that interbreeding was common among early human species. However, little was known about when, where, and how often this hominin interbreeding took place. Using paleoanthropological evidence, genetic data, and supercomputer simulations of past climate, a team of international researchers has found that interglacial climates and corresponding shifts in vegetation created common habitats for Neanderthals and Denisovans, increasing their chances for interbreeding and gene flow in parts of Europe and central Asia.
Published Elephant ancestors´ teeth evolved in response to long term changes in diet and climate in Africa
(via sciencedaily.com) Original source A new study shows that the cheek teeth of proboscideans (elephants and their ancient relatives) evolved in response to dietary changes due to vegetation changes and climate change in East Africa during the last 26 million years.
Published A climate-orchestrated early human love story
(via sciencedaily.com) Original source A new study finds that past changes in atmospheric CO2 and corresponding shifts in climate and vegetation played a key role in determining when and where early human species interbred.
Published How a massive North Atlantic cooling event disrupted early human occupation in Europe
(via sciencedaily.com) Original source A new study finds that around 1.12 million years ago a massive cooling event in the North Atlantic and corresponding shifts in climate, vegetation and food resources disrupted early human occupation of Europe.
Published Drops of seawater contain traces of an ancient world
(via sciencedaily.com) Original source New research links chemical changes in seawater to volcanic activity and changes.
Published Then vs. now: Did the Horn of Africa reach a drought tipping point 11,700 years ago?
(via sciencedaily.com) Original source If climate models predict that much of tropical Africa will become wetter with a warming climate, then why does it keep getting drier in the Horn of Africa?
Published Invasion of the Arctic Ocean by Atlantic plankton species reveals a seasonally ice-free ocean during the last interglacial
(via sciencedaily.com) Original source A subpolar species associated with Atlantic water expanded far into the Arctic Ocean during the Last Interglacial, analysis of microfossil content of sediment cores reveals. This implies that summers in the Arctic were ice free during this period.
Published Past climate warming driven by hydrothermal vents
(via sciencedaily.com) Original source An international drilling expedition off the Norwegian coast confirms the theory that methane emissions from hydrothermal vents were responsible for global warming about 55 million years ago. The study shows that the vents were active in very shallow water depth or even above sea level, which would have allowed much larger amounts of methane to enter the atmosphere.
Published Nature's kitchen: how a chemical reaction used by cooks helped create life on Earth
(via sciencedaily.com) Original source A chemical process used in the browning of food to give it its distinct smell and taste is probably happening deep in the oceans, where it helped create the conditions necessary for life. Known as the Maillard reaction after the French scientist who discovered it, the process converts small molecules of organic carbon into bigger molecules known as polymers. In the kitchen, it is used to create flavors and aromas out of sugars. But a research team argues that on the sea floor, the process has had a more fundamental effect, where it has helped to raise oxygen and reduce carbon dioxide levels in the atmosphere, to create the conditions for complex life forms to emerge and thrive on Earth.